How to Set Up a Saltwater Refugium

Refugiums are commonly used by salt water or marine aquarists. Since filters, protein skimmers, chillers and other pieces of equipment are so expensive, a refugium allows a fish keeper to have two tanks run by one set of tank equipment. The refugium is a much smaller tank where fish fry or tiny species like crabs or shrimp can be kept, which otherwise might be eaten by other fish in the main tank. Plants can also be grown without being torn apart by large fish.

Things You'll Need

  • One acrylic aquarium at least 10 gallons large
  • Tank stand or sturdy shelf
  • Aquarium lid with light attachment
  • One salt water pump
  • Air hoses as needed
  • PVC pipe as needed
  • 2 PVC L attachments for each piece of PVC pipe used
  • Single edged razor blade
  • 1 to 3 inches of live sand
  • 4 to 5 pieces of live rock (optional)
  • Water test kits
  • Aquarium salt
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Instructions

    • 1

      Rinse out small aquarium that will become the refugium. Place on tank stand. Position the refugium so that it is higher than the main tank. This helps eliminate water flow problems. Place a small amount of water in the tank to be sure the tank is level. Keep moving the tank and stand until the water is level.

    • 2

      Place the lid on the aquarium. If the lid does not have holes wide enough to fit the air hose or PVC pipe, make holes with a single edged razor blade.

    • 3

      Fit a salt water pump large enough for a 10 gallon aquarium into the aquarium lid or inside the tank, depending on the manufacturer's instructions. The pump will help draw up water from the main tank into the refugium. Water can be filtered from the refugium back to the main tank, if desired, by adding more air hose or PVC pipe from the back of the refugium down into the back of the main tank. Check that the tank is level again before adding water or the tank will be too heavy to move.

    • 4

      Fill the bottom of the refugium tank with 1 to 3 inches of live sand, or sand that has been treated with helpful bacteria and plankton. Place live rock pieces in the sand if you have them. Fill with water and aquarium salt. Test the water's pH factor, ammonia levels and chlorine to be sure it falls into the parameters for whatever creature that will live in the refugium.

    • 5

      Wait at least one week before adding any live plant, fish, or crustacean to the refugium. This will give you time to be sure the pumps are working, and that there are no leaks.